The present invention is related to a ratchet tool which can be two-way switched to easily change the position of the ratchet block.
FIG. 6 shows a conventional two-way ratchet wrench. One end of the wrench is a head section 81 connected with a handle 82. A ratchet 83 is mounted in the head section 81. A tunnel 84 is radially formed at the conjunction between the head section 81 and the handle 82. A ratchet rack 85 is fitted in the tunnel 84. The ratchet rack 85 has two opposite ratchet sections and two dents 853 in which a locating steel bead 86 is pushed by a spring 87 and located. In normal state, the ratchet rack 85 is pushed by the steel bead 86 and the first ratchet section 851 is engaged with the ratchet 83. One end of the ratchet rack 85 extends out of the tunnel 84 for a user to push so as to push the ratchet rack 85 and change the position thereof. At this time, the second ratchet section 852 of the ratchet rack 85 is engaged with the ratchet 83 and the rotational direction of the ratchet wrench is changed.
Such conventional ratchet wrench has some shortcomings as follows:
1. When working, the ratchet 83 of the head section 81 is fitted onto a bolt and the handle 82 is held to wrench the bolt. Accordingly, the stress is concentrated at the conjunction between the head section 81 and the handle 82. However, the conjunction is formed with a tunnel 84 so that the strength of the conjunction is much weakened. Therefore, when wrenching the bolt, the wrench is hard to bear high torque and tends to break at the conjunction.
2. It often takes place that a user needs to operate the wrench in a narrow place. However, one end of the ratchet rack 85 protrudes from the wrench and tends to obstruct the operation when wrenching the wrench. Moreover, the protruding end of the ratchet rack 85 makes it quite inconvenient to fit the wrench onto the bolt.
FIGS. 7 to 10 show another type of conventional ratchet wrench 9. The conjunction between the head section 91 and the handle 92 is formed with a receptacle 94 in which a ratchet block 93 is mounted. The receptacle 94 communicates with a socket 941 outward extending from the receptacle 94 through the wrench 9. The socket 941 has a dent 942 formed on a side wall of the socket 941. A driving block 95 is placed in the socket 941 and partially protrudes beyond the wrench 9 for a user to shift. A spring 97 is fitted around one end of a driving pin 96 which is fitted in a hole 952 of the driving block 95. The other end of the driving pin 96 abuts against the wall of a recess 931 formed on the bottom of the ratchet block 93 as shown in FIG. 9. One end of the spring 97 is finer, while the other end thereof is coarser. The rearmost end of the coarser end is enlarged to lean on outer side of the hole 952. The free end of the finer end has a radially extending restricting bar 971 for abutting against and locating the driving pin 96. One end of a locating pin 98 abuts against one end of the dent 942, while the other end thereof is fitted in a spring 99 and inserted in a hole 953 of the driving block 95.
When shifting the driving block 95, the rear end of the locating pin 98 is moved from one end of the dent 942 to the other end thereof. The driving pin 96 is driven by the driving block 95 to move the ratchet block 93 to the other side so as to change the wrenching direction of the wrench 9. The above conventional ratchet wrench 9 has some shortcomings as follows:
1. When shifting the driving block 95, the driving block 95 is rotated about a fixed fulcrum to drive the locating pin 98 and the driving pin 96. It is necessary for the user to overcome a resistant force for rotating the driving block 95. Therefore, it is not so easy to rotate the driving block 95.
2. As shown in FIG. 9, a spring 97 is fitted around the bottom end of the driving pin 96, while the top end of the driving pin 96 directly abuts against the ratchet block 93. The driving pin 96 itself has no resilience so that it is hard for the driving pin 96 to drive the ratchet block 93.
3. One end of the spring 97 is finer, while the other end thereof is coarser. In addition, the free end of the finer end has a radially extending restricting bar 971.
Therefore, it is troublesome to manufacture the spring 97.
It is therefore a primary object of the present invention to provide a ratchet tool in which the driving block can be easily shifted to change the position of the ratchet block. One side of the receptacle receiving the ratchet block is formed with a slot communicating with the receptacle and outward passing through the main body of the ratchet tool. A driving block is inlaid in the ratchet block. The driving block has a driving rod extending through and out of the slot to connect with a push button disposed on outer side of the main body. When pushing the push button, the driving rod is linearly moved within the slot, whereby the driving block drives the ratchet block to change the wrenching direction of the ratchet tool.
It is a further object of the present invention to provide the above ratchet tool in which the section of the driving rod extending out of the slot is a threaded section for screwing with the push button. By means of pushing the push button, the driving block can be easily switched.
It is still a further object of the present invention to provide the above ratchet tool in which the middle of the cavity is straight and not arched. Therefore, two ends of the cavity are farther from the leaning section of the spring, whereby the spring will push two ends of the cavity to move the ratchet block. This makes the ratchet block more truly located.
It is still a further object of the present invention to provide the above ratchet tool in which two ends of the spring are both tapered so that the contacting area between two ends of the spring and the leaning section and the cavity is reduced. This reduces the resistance against the shifting of the spring. Therefore, the ratchet block can be easily switched.
The present invention can be best understood through the following description and accompanying drawings wherein: